Tire cooling arrangement



Jan. 16, 1951 c. B. lSHAM 2,538,563

TIRE COOLING ARRANGEMENT Filed April 6, 1948 2 Sheets-Sheet 1 Ill i571 INVENTOR. CHARLES E. ISHAM ATTORNEYS C. B. ISHAM TIRE COOLING ARRANGEMENT Jan. 16, 1951 2 Sheets-Sheet 2 1 JNVENTOR.

" CHARLES 5. 13/4/11 4 ATTORNEYS Patent ed Jan. 16, 1951 V fits-8,569

momma ARRANGEMENHZ:

' enamels:-lsum;;nniwa statesm North. Sacramento; 1 ('falifjf Ann oatti n -Atnnil .6; 1948;;Snial 0 19,34 viclaims; (e1. nae-way It; is well known that) deterioration and failure; of tire, casings. on automobiles and;.truc1is ,.,as@ distinguished from punctures, andzjsi'milar. acciie dental ruptures, is, the. result 0L. heat generatied'lin the. tire casing; by. itsflexure andlliy; friction as, the. vehiclelmnvesover the roadway; in excess of. whathcan. dissipatedlfromithe; casing, by the .relat'ive .aiiz. Inaproperlyx inflated: tire .on a, reasonably good -roadlsurfaca.thimg reatyest heating occurs. at; the tread', ,and?.-here, or.;at, the. juncture. between. the. .t'readi and; the; side. walloccur a large. number of.,.blbwo ut .andi other.v failures.

It is. a general object of; the. presentinvention; to, provide. means whereby, tlielheatthusvg enerat ed,', particularly, in the treadsection may; be; transmittedt'o anddisSipated from the sidewall portion of the tire,,allj.by vittueofithe;repeated; road; contacts and the action. resnltihgyonlthe, tire therefrom,, with. the result. that; the. action.

which pro'ducesitlielieat itSBlffifieOlZS dissipation of that heat:

More specifically it. isanlolijectofithe-present. invention to provide heatt'ransfr meansnmfefr ably in the. form of a coolantafilled conduit, wholly incorporated within the? tire casing, and. arranged to" circulate the 'coolant -liquidjorigas from a heated portion, such as the. tread nor:- tion ofthe'casing, to andcompletelytllrougli a;- relatively cooler" portion; such. as the sidewall}, and back again when sufl-lciently cooled; picking up the heat' at' the, tread" portion and giving it. up byreason of-the fact that itmustpass through. and remain within the relatively'cooler sidewal portion, where it can be dissipatedjjor a;sufficient; time to beadequatel'y cooled, all to theulftimate" end of avoiding excessiveoverheating in? anyone; part of the tire casing; an'd" thereby ofavoiding the destructive" or' dangerous effects ofsuch heating;

A still further objecfi is t-lieprovision off such cooling means incorporating" multiple coolant?- In.- the accompanying, drawings. the: inventionv isshown in. certain. practical...formgofg-executiom suchas illustrate the pr-incipleslofltheeimlention:

andas are presently preferred bymen itlbeinge 65 understood? that various cliangesimw beimade inz.

. with the latter.

Figure. 5..is-, antenlarged. detail.'sectionahview longitudinally of. the. conduit, showings one-oi: the: circulation-controlling, valves-I closed; and; Figure 6; is ,a..similar View, showing. the. same open.

Eigurefl, is: a. detail; sectional viewot? the side- Incorporated.- withina-tha casing; constel ation! are/conduits; eaohi g nerally designated h5g4 =.th,e: numeral -2,; which 101116.65 leastsaasectiontjai: locatediwithinlthe:tread pontionl I 3iiof1'the;casing, and; a:- section 2i. loeaited:.rwithi,n .on'e -ot. the side wallgportions. Rreferably there-are twoiside wall. sections so.- than the. sidewall; l sl 7 contains the-section. Zl. anda-the sidewalk l;2;-.containszthes section- 2'2 oil-the conduit-12.. The. conduits have: resiliently: flexiblewallsgwhenem' they may-dis.- tencL-and; contract;-, and. the; section; :23 is cansedi so, toeontract byithe pressure upqm-theeroadwax R in-the mannenbest. shown inaFigme=3 as this particular:- secltion bearsr theeweightt of: the? autos mobile, This-squeezing; ofylthee tread? sectiqnd'? of; the. conduit: squeezes the coolant. fluidtswit-hl.

the tread section 23, because by preference the sidewall sections of .the conduit are of much greater volumetric capacity in the aggregate than the corresponding tread section 23. As soon as the tread which has been thus squeezed rolls from contact with the roadway, the resilience of Figure 2. The nearer they can lie to the outer surface of the casing the more efiicient is the the tire casing and of the conduit tends to swell the tread section 23 back to its normal size, and

create a negative pressure in the tread section,

but circulation-controlling means at 3, as is illusserve to prevent such return by the same path,

although similar circulation-controlling ineans' at, 3l,perrnitexce s s liquid which had previously distended the'sidewall section 2!, butwhich, by now has circulated through the latter, and has been so cooled, to flow again into the now extend ing tread section 23, without return. Thus a closed circulation is set up, in the preferred arrangement. In the arrangement shown the circulation occurs from one side of the tread section 23 past the non-return valve 3 into the sidewall section 2|, thence back past the non-return Valve means 31, through the other part of the tread section 23, and thence to the opposite sidewall section 22 past non-return valve means 3?, andjthence past non-return valve means 33 back'to the original part of the tread section 23.

So" by the alternate flexure and squeezing of 3 the? tread section, caused by its repeated contacts of a given section of the tire as it rolls along the roadway, circulation completely through the conduit in a singledirection is set up within each such conduit 2.

The'form of the non-return valve, such as that at 3, isknown, and consists, for example, of complemental rubber shoulders 35 and 35 which ma spread apart under the influence of pressure from the left as seen in Figure 6, but

which-upon closing down will prevent flow in the reverse direction. Such valves are known as Mital valves. e

As shown, however, each such conduit occupies a single cross-sectional zone of limited peripheral extent," and there are several such' conduits peripherally spacedab'outthecasingas is indicated in'Figure 2.' 'Indeed, they may be manufactured by forming the conduits between two sheets of rubber, or by laying 'a rubber tube upon a- =rubber' sheet or between two rubber sheets, and the conduits may be supplied in the form of in'dividual or connected patches of rubber sheeting,- with or without cord material embedd'ed therein, which may be applied as one of the layers wrapped about the carcass in the manufacture of the casing. Preferably, there are a number of independent or at least non-connee-ted conduits, for the reason that if the casing is punctured'in the region of one such conduit, and leakage of fluid therefrom occurs, the fluid isilstill retained in all the other conduits and the cooling effect on the casing is not greatly reduced. Such arrangements are made clear in 'trated in detail in Figures 5 and 6, preferably cooling effect, yet they must be embedded deeply enough to avoid damage from scuffing along curbs, etc.

The cooling effect is brought about by reason of the transmission of the fluid, with heat picked up in its passage through the tread section 23, to the relatively cooler sidewalls H Or 12 of the casing, there by reason of its unidirectional flow through the entire conduit to transmit the excess heat to the sidewall, and thus to dissipate it by conduction to the relative air. If it is desired toincrease the cooling effect, there may be incorporated in the sidewall a radiator element such as the metallic coiled spring device as shown'at '4 in Figure '7, which is embedded inthesidewall of the casing in heat exchange relationship with the conduit embedded therein, and which in part projects through the sidewall toor into the air, and thus more readily dissipates the heat which it acquires from the liquid within the conduit.

= Since the conduits are each of large volumetric tions 2 I volume, and are resiliently expansible, such ex-' a, HG

pansion will accommodate any thermal increase in the liquids volume. Theliquid should have a low freezing point, although if frozen it will soon thaw as the tire rolls over the roadway. It should have a high boiling point, and should not be harmful to the rubber composition which it contacts. Glycols, or like alcohols, willbc found well adapted to such use, but no restriction is intended in the choice of a suitablefliquid. Indeed, a gas may be used instead'of a liquid,

7 as the coolant, or if the pressure generated by directionally from change of phase is not excessive, the coolant .may be ,a liquidthrough a low temperature range and a gas at higher temperatures, perhaps changing phase as it circulates from ;tread section 23 to sidewall sections, and return.

I claim as my invention: 1 r

l. In atire casing having. a tread subject to heating from repeated road contacts,.and sidewalls relatively less subject to heating, a coolantfilled conduit incorporated in part within the tread to receive heat therefrom, and in part within the sidewall to deliver heat thereto, for flow of the coolant through said conduit from the tread to the sidewall, and again to the tread, as the casing flexes and means in said conduit to constrain flow of the. coolant unithe. tread portion and throughout the sidewall portion before returning it to the tread portion.

2. A tire casing as in claim 1, includingradiator means lying in part within the sidewall portion,-in heatexchange relation to the conduit therein, and in part extending to the exterior of the casing, for dissipation of heat'to the such road contact and squeezing to flow from aasaua the sidewall section back into the now-relaxed tread section.

4. A tire casing as in claim 3, the circulationconstraining means including two non-return valve means in the conduit arranged the one to block return flow from the sidewall section to the tread section, and the other to block return flow from the tread sectionto the sidewall section, whereby the liquid flow progresses unidirectionally with each road contact and consequent squeezing of the tread section of the conduit.

5. A tire casing as in claim 3, including a plurality of such conduits, each independent of the others and complete in itself, spaced peripherally about the casing.

6. A tire casing as in claim 3, wherein the conduit extends from an initial point in thetread to one sidewall, thence by way of the tread to the opposite sidewall, and back to the initial point in the tread.

7. A tire casing as in claim 3, characterized in that the sidewall section of the conduit is of large volumetric capacity and the tread section is of small capacity.

CHARLES B. ISHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

